The trial of a California man charged him with murdering his girlfriend’s 18-month-old daughter began this week, as reported by FOX 5.

Wiliey Foster, 28, has been arrested for killing infant Leah Brown-Meza in December 2016. Authorities made the arrest shortly after finding the toddler’s body in a motorhome. Brown-Meza’s mother, Lillie Brown, has also been charged with child endangerment, though has not been implicated in the murder.

During Foster’s murder trial, which began this week, the defense attempted to paint Brown as a negligent mother who didn’t check in on her daughter all night, instead taking the word of the defendant that she was fine.

“She didn’t want to seek medical care for that child because the father of that child was trying to get custody away from her. He felt she was a bad mother because he thought she was using drugs,” said defense attorney Jan Ronis.

Brown-Meza was found with a broken arm, burned feet and numerous head injuries. Brown discovered her daughter’s body, which had turned blue and cold, according to court testimony.

The infant’s blood was found on Foster’s clothing but, as court records indicated, he had “more important things to do” than address the dead child.

“Detective Patterson is telling him ‘calm down – a baby died today.’ And he says, ‘I have more important things to worry about than a dead baby,'” said Deputy District Attorney Chantal De Mauregne.

The trial should wrap up next week. The infant’s mother pleaded guilty to child endangerment but has yet to face a sentencing hearing.